Combine the brown sugar, butter, and corn syrup in a medium sauce pan and cook over highheat for 5 minutes. Remove the pan from the heat and stir in the baking soda. Thoroughly combinethe popcorn and the marshmallows in a large metal or heat resistant glass bowl. Drizzle thesugar mixture over the popcorn to coat it, then gently stir in the graham cookies and chocolatechips, incorporating them evenly throughout the mixture. Let the mixture set until cool enough tohandle, then using buttered plastic sandwich bags on your hands, form the mixture into golf ballsize balls. Store in airtight container.